Launched in 1993, 1O1O is the highly regarded premium brand of CSL Mobile Limited. Known for its award-winning customer services^. 1O1O offers a premium 5G mobile lifestyle experience to suit discerning customers, comprising extraordinary network speed, innovative audio-visual entertainment, intelligent products and consumer applications that differentiate the revered 1O1O brand from all others.

^ 1O1O won "Service Retailer of the Year (Telecommunications)" at the Hong Kong Retail Management Association's "Mystery Shoppers Programme" from 2009-2012.